Milling machine transmission and electric control therefor



y 1936- w. D. ARCHEA 2,042,245

MILLING MACHINE TRANSMI$SION AND ELECTRIC CONTROL THEREFOR Filed Jan; 2,1935 9 Sheets-Sheet l WALTER .D. Hzcnsn y 1936- w. D. ARCHEA 2,042,245

MILLING MACHINE TRANSMISSION AND ELECTRIC CONTROL THEREFOR Filed Jan. 2,1955 9 Sheets-Sheet 2 5 1 4/6 4J3 "-n m WALTEKD. HRCHEH May 26, 1936- w.DJ ARCH EA 2,042,245

MILLING MACHINE TRANSMISSION AND ELECTRIC CONTROL THEREFOR Filed Jan. 2,1935 Sheets-Sheet 3 Himmweumnnkcm y 26,1936 w. D. ARCHEA 2,042,245

MILLING MACHINE TRANSMISSION AND ELECTRIC CONTROL THEREFOR Filed Jan. 2,1935 9 Sheets-Sheet 4 y 1936- w. D. ARCHEA 2,042,245

MILLING MACHINE TRANSMISSION AND ELECTRIC CONTRQL THEREFOR Filed Jan. 2,1935 9 Sheei is-Shee t 5 lni l wue/wtoo WH LTER D. ARCHEH May 26, 1936.w. D. ARCHEA MILLING MACHINE TRANSMISSION AND ELECTRIC CONTROL THEREFORFiled Jan. 2, 1955 9 Sheets-Sheet 6 HUM;

y 1936- w. D. ARCHEA 2,042,245

MILLING MACHINE TRANSMISSION AND ELECTRIC CONTROL l HEREF OR Filed Jan.2, 1935 9 Sheets-Sheet 8 gwue/wto'n WALTERD HRcHEA May 26, 1936. w. DARCHEA 2 4 45 MILLING MACHINE TRANSMISSION AND ELECTRIC CONTROL THEREFORFiled Jan. 2, 19:55 9 Sheets-Sheet 9 mm M w Z2 WALTER JJ. HR EA PatentedMay 26, 1936 UNITED STATES MILLING MACHINE TRANSMISSION AND ELECTRICCONTROL THEREFOR Walter D. Archea, Cincinnati, Ohio, assignor to natl,Ohio, a corporation of Ohio I Application January 2, 1935, Serial No.124

The Cincinnati Milling Machine 00.,

Cincinzs Clainis. (or. 90-21) This invention relates to machine toolsand more particularly to an improved transmission and control mechanismfor a milling machine.

One of the objects 01' this invention is to pro- 5 vide a simple compacttransmission 'unit for imparting selectively a plurality of relativelyslow or feeding rates between the cutter and work or a relativelyiast orquick traverse rate. Another object of this inwention is .to provide 10an improved control mechanism which will be immediately responsive totrip operation by the I .table for shifting the'various controlclutches,

thereby enhancing the trip accuracy of the maprovide a self-containedtransmission unit.

which may be constructed and assembled as a unit independent the machineand automati- 25 cally coupled with the driving part for the table uponassembly with the machine.

. An additional object of this invention is to provide -improvedinterlocking mechanism be tween the tool driving mechanism and the feed-30 ing mechanism 01' a-machine tool; improve the operatingcharacteristics-ofthe machine where by starting or changing or rates.during operation may be effected in a smooth and eflicient manner; andgenerally improve the operating and control characteristics of a machineof the class described. Other objectsand advantages oi-the presentinvention should be readily apparent by reference to the followingspecification, considered in til 40 conjunction with the'accompanying.drawings.

forming a part thereof and it is to be understood that any modificationsmay be made in the exact structural details there shown and described,

. within the scope of the appended claims, without 45 departing from orexceeding the spirit of the invention. 4

Referring to the drawings in which like refer- Figure 5 is a detail viewtaken on the line 5-5 of Figure 4.

Figure 6 is a detail view taken on the line-H of Figure 4. r

Figure '7 is a-detail view taken on theline 'I-l 5 of Figure 4.

Figure 8 is a section on line 8-8. of Figure 4 showing the details. ofthe overrimning clutch mechanism.

Figure 9 is a detail sectional view taken on the 10.

line 9-9 of Figure '7.

Figure 10 is a sectional view through the control cams as viewed on lineIii-40 of Figure 3.

' Figure 11 is an elevational view. of the control bracket with thefront cover removed. 5

Figure 12 is a section on the line l2-I2 of Figure 3 showing theposition of the various control solenoids.

Figure 13 is an expanded detail view oithe back lash eliminatingmechanism for the table lead screw.

Figure 14 is a detail view of the starting control lever and interlockswitch as viewed on the line l4=l4 01 Figure 1.

Figure 15 is a detail view of the hydraulic pressure supply pump andconnections thereto as viewed'on the line l5l5 01 Figure 2.

Figure 16 isja section through the control bracket as viewed on the linelG-IG of Figure 1.

Figure .17 is a section through the control bracket as viewed on theline l'|l'l of Figure 16 showing the trip and stop plungers andconnections thereto.

Figure 18 is a section on the line-l8l8 of Figure 16 showing the detailsof the hydraulic control valve.

Figure 19 is a detail view on the line l9-l9 of.

Figure 18.

Figure 20 is a detail view on the line 20-22 of Figure 18. p 4

Figure 21 is a diagram of the electrical con- 1 'trol circuit.

- Figure 22 is a sectional view showing the details of the tool spindletransmission.

Figure 23 is an enlarged detail view through the feed rapid traversecontrol clutch as viewed on the line 23-23 of Figure 3.

Figure 24 is a detail section on the line 24-24 of Figure 23. l v

Figure 25 is a detail section on .the line 2525 of Figure 3.

Figure 26v is a detail section on'the line 26-28 4 of- Figure 2.

Figure27 is an enlarged detail view 01' the feed 1 rapid traverse clutchshifter fork. 5 Y Figure 28 is a detail section on the line 28-28 ofFigure 10.

29 is a detail section on the line 29-29 of Figure 10.

Figure 30 is a section on the line 30-30 of Figure 10 showing thedetails of the interlock control clutch.

Figure 31 is a detail section on the line 3|3| of Figure 11.

Figure 32 is an enlarged detailed section on the line 32-32 of Figure12.

Figures 33 and 34 are expanded views of the cam tracks in the controlcams.

Figure 35 is a detail view of the upper end of the main control plunger.

Figure 36 is a section on the line 36-36 of Figure 11.

In Figure 1 the reference numeral l0 indicates the bed of the machinehaving guide ways formed on the top thereof for receiving and guiding awork table l2. Uprising from the back of the bed is a column l3 havingvertical guide ways |4 formed upon one face thereof for receiving aspindle carrier I5 in which is journaled the tool spindle l6.

The transmission for actuating the tool spindle is shown moreparticularly in Figure 22 and includes a prime mover I! which isconnected by suitable motion transmitting means, such as the drive chainHi, to the sprocket wheel l9 secured to the end of the drive shaft 20'.This drive shaft extends horizontally through a portion of the base ofthe column l3-and is connectible by suitable means, such as the frictionclutch 2|, to a driving sleeve 23 upon which is mounted for freerotation a pair of opposed bevel gears 24. These gears intermesh with acommon bevel gear 25 keyed to the end of a vertical splined shaft 26. Aclutch member 21 is splined on the sleeve 23 and has clutch teeth 26formed on opposite ends thereof for selective interengagement withsimilarly formed clutch teeth carried on the opposing faces of the bevelgears 24 for effecting reverse rotation of the shaft 26. A shifter fork29 is fixed to a shifter rod 30 for movement of clutch 26, the shifterrod having rack teeth 3| formed thereon interengaging with a pinion 32fixed to the end of a. manually operable shaft not shown.

The friction clutch 2| has a shiftable member 33 which is connected by apin 34 to a longitudinally movable rod 35 which at the left end has aspool 36 secured thereto by which the clutch may be engaged anddisengaged by longitudinal movement of the rod. A shifter fork 31 ispivotally mounted at 3 8 for interengagement "with the spool and has aball receiving socket 39 formed therein for receiving the ball endedlever 40 which is pivotally mounted at 4| in a fixed portion of themachine bed. i

The lever 46 has a crank arm 42 integral therewith which is connected bya link 43 and crank 44 to the shaft45, which shaft extends through theend of the bed for receiving an operating handle 46 which is shown inFigure 1. When the handle is moved upward in that figure the clutch isengaged and when moved downward the clutch is disengaged and a frictioncone surface 41 integral with the member 33 is interengaged with a fixedcone surface 46 which serves as a brake for immediatelystopping the toolspindle.

The shaft 26 which extends into the spindle carrier is splined into abevel gear 49 which intermeshes with a bevel gear 56 fixed to the end ofa shaft 5|. This shaft is connected through change gears, indicatedgenerally by the reference numeral 52, to thepinion shaft 53 whichcarries a pinion 54 intermeshing with the large spur gear 55. -The spurgear is fixed for rotating a sleeve 56 which has a splined connectionwith the tool spindle 51. The forward end .of the tool spindle isanti-frictionally iournaled in a quill 58 and is fixed for axialmovement therewith, this movement being effected through conventionalmeans comprising a spiral gear 59 which intermeshes with rack teeth 60formed on the periphery of the quill, the spiral gear having a spur gear6| integra1 therewith which is interengaged by a manually rotatablebevel pinion 62. This rotation may be effected by the manually rotatablehandle 63 carried on the end of a shaft 64 which supports the pinion 62.

The tool spindle may thus be driven in opposite directions and atvariable speeds and may be vertically adjusted on the guide ways H bylater also serves to automatically control the rotation of the spindlein accordance with movement of the table. The table is reciprocated bymeans of a lead screw 66 which is fixed against rotation in oppositeends of the table and which passes through a pair of rotatable nuts 61and 66, which are shown in Figure 13, and which are anti-frictionallyjournaled in a fixed part of the bed of the machine. The nut 61 carriesa spiral gear 69 on its periphery, the teeth of which are at a differentangle to the teeth of a spiral gear I6 carried by the rotatable nut 66.The spiral gear 69 meshes with a spiral gear II and the gear 16 mesheswith the spiral gear 12, the gears H and 12 being fixed to a shaft I3for joint rotation, the shaft, however, being axially movable in bearing14.

The spiral gears are rotated by a pinion 15 which is fixed to the shaft13 and intermeshes with a wide spur gear 76 as more particularly shownin Figure 3. The two pairs of intermeshing spiral gears of differenttooth angle constitute a backlash eliminating mechanism which operatesin the following manner:

When the shaft 13 is moved toward the right as by means of a fork 16engaging an annular groove 11 in the sleeve the spiral gears 69 and 10will be rotated unequal amounts, whereby one will engage one side of thethread of the lead screw and the other will engage the other side of thethread to take out all backlash. The particular side of the lead screwthread engaged by the nut 66, for instance, will depend upon thedirection of rotation of the nut so as to prevent locking up of thedevice and therefore two hydraulic cylinders 11 and 16 havebeenprovided, one of the cylinders receiving pressure to effect urge in onedirection when the rotation is clockwise and the other cylinderreceiving pressure when the rotation of the nuts is counterclock- Sincethe specific details of this backlash eliminating mechanism forms nopartof the present invention it is believed sufficient to state thatpressure is admitted to the cylinders 11 and I8 selectively anddepending upon the direction of table movement to eliminate backlashduring feeding movements of the table and that the pressure'is the samein both cylinders durpline Shaft 8| which is journaled at 82 in the bedof the machine and has an integral collar 83 which serves to positionthe shaft in an axial direction. This shaft has a keyed end 84 which isreceived in the splined bore 85 of the hub 88 of a bevel gear 81, whichgear is fixed for rotation in the gear box 88. When the gear box isremoved from the end of the machine it is automatically disconnectedfrom the end of shaft 84 and thereby breaks the driving connection tothe table lead screw. This makes it possible to construct and assemblethe mechanism in the gear box 88 independent of the machine and thenassemble it with the bed of the machine and automatically establish adriving connection with the table lead screw, the collar 83 holding theshaft 84 in the proper position during the assembly of the hub 85thereon. The gear 81 constitutes the final drive gear in the feed boxfor moving the table at various feed rates or at a rapid traverse rateand is actuated to effect these various rates by the followingmechanism, reference now being had more particularly to Figures 2 and 3.

A prime mover 89 is mounted on a bracket 98 carried by the gear box 88and isconnected through an Oldham coupling 9I to shafts 92,anti-frictionally journaled in the feed box and carrying a pinion 93.This pinion intermeshes with a spur gear 94 which is secured to a sleeve95 which is anti-frictionally journaled as by'the bearings 98 for freerotation relative to a supporting shaft 91. The sleeve 95 has a bevelgear 98 fixed to one end thereof which is connected by an intermediatebevel gear 99 to a bevel gear I88'which is mounted co-axially'of bevelgear 98 but which will rotate in an opposite direction with respectthereto. The bevel gear I88 is also supported on anti-friction bearingsI8I for free rotation with respect to the supporting shaft 91. It willnow be seen that the gears 98 and I88 are rotated in opposite directionscontinuously during actuation of the prime mover and means have beenprovided for alternately connecting these gears for rotation of shaft 91and which thereby constitutes a reversing mechanism. The bevel gears 98and I88 have multiple disc friction clutches IM and I82 associatedtherewith and an intermediate shift-.

able member I83 serves to alternately couple these gears through thefriction clutches to the shaft 91.

The shaft 91 has a gear I84 keyed at one. end thereof, adjacent to gear94, which intermeshes with a spur gear I85, more particularly shown inFigure 3, and which is directly over gear-I84. The gear I85 is mountedfor free rotation and supported by anti-friction bearings I88 on asupporting shaft I81. This gear has an extended hob I88 in which isenclosed a multiple disc friction clutch I89 by which it may beconnected by the shiftable member 'I I8 to drive shaft I81. Thedirection of rotation of this drive will depend upon the position of thereversing clutch the feed transmission. As shown in Figure 2 this pinionmeshes with a large spur gear H2 which is keyed to asleeve Il3 mountedfor free rotation in anti-friction bearings I I4. The sleeve carries'fapinion, I t8 which meshes with gear H8 of the couplet II1, which in turnis keyed on a shaft H8. The other gear II9 of the couplet.

meshes with a gear I28 keyed to the shaft I2l which has one endjournaled at I22 in the bore "of the sleeve H3 and the other end I23journaled in the hub of spur gear I24. The shaft I2I also has a sleeveI28 keyed thereto on which is formed a pinion I28 which meshes with alarge spur gear I21 directly over it as shown in Figure 3, this spurgear having a pinion I28 integral therewith, this gear and pinion beingmounted for free rotation relative to a supporting shaft I29. The pinionI28 meshes with a large spur gear I29 directly beneath it and is mountedfor free rotation relative to the shaft I23. The gear I29 has anextended hub I38 upon which, as shown in Figure 2,.is mounted a collarI3I having a keyed connection I32 with said hub and thereby rotatabletherewith. It will also be noted that shaft I2I has a reduced portionI33 upon which is keyed a' sleeve I34, having in turn keyed to itsperiphery a pinion I35. In the arrangement of the parts as shown, thegear I35 meshes with keyed to the shaft I23 whereby the end portion I33of the'shaft is rotated at the same rate as pinion I28 and therefore thegear I35 will dri ve the gear I38 and shaft I29 independently of thereduction effected through the train of gears I28, I21, I28 and I29. Thegears I35 and I38 are removable so that they may be interchanged orother. pairs of gears substituted therefor whereby a first series offeed rates may be obtained. In addition, the collars I3l and I38 arealso removable and the gears I35 and I38 may be substituted in theirplace for effecting a second series of feed rates, the collars in thiscase being then mounted in the position now taken by the gears I35 andI38. When these changes are made the cover plate I39 is removed;

The shaft I29 extends into the interior of the feed box and is providedwith a pinion I48 for driving the large spur gear I mounted for freerotation with respect to shaft I81. It will be noted that the gear I isco-axial of the gear I85 and the shiftable member 8 constitutes a feedI81 for rotation therewith. The keys I45 are' fixed with the member H8for movement therewith and each has a bevel end I48 which operates on abell crank I41 for applying frictional pressure to the plates I48 of themultiple disc friction clutch, indicated generally by the referencenumeral I89, whereby the member I88 will drive the shaft I41 at a rapidtraverse rate.

The opposite end I49 of keys I45 is also beveled for engaging a bellcrank I58 which applies pressure to the plates I5I of a second multipledisc friction clutch to initiate rotation of gear I4I. This frictionclutch is so adjusted as to initiate rotation and is utilized solely forthat purpose so as to prevent shock when the drive is started, therebeing clutch teeth I52 formed on one face of the member IIO forinterengagement with similarly formed clutch teeth I53 on the hub ofgear I4I for positively driving the same. The parts are so positionedthat the friction clutch will engage before the positively drivingclutch teeth interengage, whereby the parts are slowly moving at thetime of the interengagement of the positively driving clutch teeth.

The member II 0' may be moved to a central position with respect to thefeed and rapid traverse clutches whereby both the feed transmission andthe rapid traverse transmission are disconnected from the table whichserves to stop the table movement. Thus the member H0 is not only afeed-rapid traverse selector but also a means for stopping the table.

When the clutch H0 is in a neutral position the table may be rotatedmanually through the following means. A gear I54 is mounted for freerotation on the end of shaft I01 and normally connected thereto when themachine is stopped by a multiple disc friction clutch I55 which isoperated by a shifter spool I56. The gear I54 meshes with a pinion I51keyed to the end of a rotatable shaft I58 which has clutch teeth I59formed on the outer end thereof. This end of the shaft is bored toreceive a plunger I60 which carries a manually operable handle I 6|having a hub I62 on which is formed clutch teeth I58 for engagement uponaxial movement with the clutch teeth I59. Simultaneous with thismovement of the plunger a second clutch member I64 which is connected bya cross pin I65 to the plunger I60 is moved axially to separate theclutch teeth I66 from the clutch teeth formed on the member I61, whichmember is fixed as by screws I68 to the bed of the machine. A spring I69is interposed between the end of the plunger W0 and the bottom of thebore in the shaft I58 for normally urging the plunger outwardly wherebythe manually operable handle is disconnected from shaft I58 and theshaft is in turn connected by the clutch member I64 to a fixed part ofthe machine so that it cannot rotate. The object of this is that whenthe machine is being operated by power the gear I54 is held againstrotation so that upon stoppage of the table and the throwing of shifterspool I56 the shaft I01 may be braked through the friction clutch I55and the temporarily fixed gear I54. Upon axial movement of the plungerI60, however, the gear I54 is no longer locked and may now inturn-rotate through the friction clutch, the shaft I01, and through theinterconnecting bevel gear, the shaft 84. The friction clutch I55 thusserves as a brake to stop the machine and also serves as a driving meansduring manual operation of the table. The clutch I56, the feed rapidtraverse selector I I0 and the direction determining member I03 areadapted to be shifted by an intermediate power means under manualcontrol of the'operator or under automatic control from the movement ofthe work table.

The power operable means for shifting the various control clutchesincludes a first power rotatable cam I10, Figure 3, which determinesfeed, rapid traverse or stop of the table and -a second rotatable camI1I, Figure 2, which determines the direction of movement of the table.In other words, the first cam has three positions and power rotation tothese three positions is controlled by three solenoids I12, I13 and I14and in such a manner that energization of these solenoids in the orderrecited will position the control clutches to effect respectively feed,stop or rapid traverse. Another pair of solenoids. I 15 and I16 controlsthe shifting of the reversing clutch, energization of solenoid I 15,positioning the parts to cause movement of the table to the 5 left andenergization of solenoid I16, causing movement of the table to theright. There are thus five solenoids, anyone of which, when ener gized,will cause movement of the respective cam controlled thereby to adefinite position to produce a definite result.

The energization of these solenoids is controlled by a single plungerwhich operates on suitable switches, the plunger itself being actu--ated either manually or automatically. This plunger I11 is shown moreparticularly in Figures 11 and 16 and is movable to six differentpositions, which correspond to six different positions of the manualcontrol lever I18. This lever is supported as by an integral ballportion for universal movement in the control bracket I and has a ballshaped end H which fits in a hole I82 formed in the oscillatable andaxially movable lever I83. This lever has a second hole I84 formedtherein for receiving the ball ended pin I85 which projects from theside of the plunger I11. The lever i 83 is mounted for oscillation andaxial movement upon a pin I86, alsofixed in the bracket I80. From thisit will be seen that if the lever I18 is moved counterclockwise, asviewed in Figure 16, that the lever I83 will be axially moved toward theleft, thereby causing rotation through member I85 of trip plunger I11.Furthermore, it will be evident that if the lever I18 is moved up ordown with respect to the plane of the drawing that the lever I83 will beoscillated about the pin I 86 and thereby move the plunger I11 up ordown in a similar manner.

The lever I 18 has six positions and in its position shown in Figure 11it will cause a, feeding 4o movement of the table to the left. The otherfive positions to which the lever may be moved are indicated by the dashand dot lines I81, I88, I89, I90 and I9I, Figure l1, which positionscorrespond respectively to rapid traverse left, rapid 45 traverse right,feed right, stop right, and stop left. This means that the plunger I11is rotat= able to two positions and axially movable to three positions,whereby a. total of six positions is possible.

Hydraulic means have been provided for detenting the plunger I 11 andthe control lever I18 in these six different positions and consists of avalve block I92 having plungers I93, I94 and I95 reciprocably mountedtherein. The plunger 55 I11 has an axially elongated lug I96 projectingfrom the side thereof as shown in Figure 19 which interengages a slotI91 formed in the side of plunger I93. Plunger I11 also has an annulargroove I98 in which fits a roller I99 attached to 60 the end of a bellcrank 200 mounted for oscillation on a fixed pin 20I. This bell crank isconnected as shown in Figure 20 by a bolt 202 to a link 203. This linkcarries a pair of pins 204 and 205 which, project laterally from thelink 65 into notches 206 and 201 formed in the side of plungers I94 andI95 respectively.

Hydraulic pressure is supplied to the valve block from a pump 208 whichis driven from the continuously rotating shaft 209 which carries the 70bevel gear 99 as shown in Figure 2. The shaft 209 has a gear 2I0 meshingwith spur gear 2 mounted. on shaft 2I2 which is journaled in a bearingM3 and connected by a coupling 2 to the end of the pump shaft 2I5. Thispump has 75 in diameter than the adjacent spools 223 and 224' wherebypressure entering the space 225 has a differential efiect and causesmovement of plunger I93. For instance, in the position of the partsshown in Figure 18 pressure is acting upon the left side of spool 222and on the right hand end of spool 224 so thatla resultant .in thedirection toward the right is produced which rotates the plunger I11until the end of the plunger I93 abuts L the adjustable stop 225. Thisstop consists of a bolt threaded in a fixed part of the bracket and alock nut 221 whereby itmay be locked in a suitable position. When theplunger I11 is rotated counterclockwise, as viewed in Figure 16, thespool 222 will move toward the left and immediately upon passing theport 229 the fluid pressure will ate completion of the rotating movementuntil the end of spool 224 hits the end plate 229.- The plunger I93 thushydraulically detents plunger I11 in its two rotative positions andregardless of its vertical position.

In a similar manner the plunger- I94 is provided with an enlarged spool239 movable relative to pressure port 23I so that immediately uponpassing the port in either direction the movement will be automaticallycompleted. The plunger I95 is also provided with an enlarged spool 232position vertically and therefore the bell crank 299, shown in dash anddot lines, may be moved clockwise upon upward movement of plunger I11 orcounterclockwise upon downward movement of the plunger. Assuming for themoment that the bell crank is moved counterclockwise due to up- .wardmovement of the plunger which means that the bolt 202 will move towardthe left as viewed in Figure 18. This movement will tend to carry thelink 293 along with the bolt but the upper end of the lever cannot movetoward the left against movement until plunger I95 has returned to theposition shown in Figure 18. It will now be seen that upon upwardmovement of the plunger I11 from its central position shlftingof plungerI95 will be caused and thereby hydraulic detenting of plunger I11 in itsupper or rapid traverse position and regardless of its rotativeposition. 5

If the bell crank 299 is assumed to move downwardfrom the position shownit will tend to cause movement of the bolt 292 in a counterclockwisedirection about the pin MI, and also tend to carry the link 293 in thesame direction. But 10 the lower end of the link is in engagement withplunger I 95 which is already in its extreme right position and cannotmove any further in that direction, whereby the link will be pivotedabout the pin 295 as a center and cause movement of 5 plunger I94 towardthe right. This movement will tend to hold the interlock pin 235 inengagement with plunger I95, preventing movement thereof until plungerI94'has returned to its central position. It will now be seen that theplunger 20 I11 is hydraulically detented in any one of the six positionsto which it may be moved.

In addition to hydraulically detenting the plunger I11 rotatively theplunger I93 also 'deter-. mines the operation of the backlasheliminating 25 means. In other words, as previously stated, pressure isadmitted to cylinder 11 of the backlash eiiminator when the feedmovement is in one direction and it is admitted to cylinder 19 when thefeed movement is in the opposite direc- 3 tion. If, then, the directionof movement of the table is changed, as from feed right to feed left,the .pressure must be reversed on the backlash eliminator. Thisisaccomplished in the following manner.

When the plunger I93 is in the position shown the pressure from port'228 is connected to. port 239 from which it passes throughinterdrilling to the annular groove 239 and port 249 formed adjacent theplunger I94.

When the plunger I93 is shifted to its extreme left position the port229 is then connected to port 24I, which by interdrilling is connectedto port 242 formed adjacent of the plunger I94. A

cannelure 243 formed in the plunger I94 is ef- 45 fective when plungerI94 is in the position shown in Figure 18 to connectport 249 to port 244and a second cannelure 245 interconnects port-242 with port 246. Theports 244 and 245 have channels ,241 and 248 respectively connectedthereto 50 which lead to the backlash eliminating cylinders 11 and 18.It will be remembered that the plunger I94 is in a feed position inFigure 18 which makes it possible for the plunger I93 to alternatelyconnect pressure to thebackla'sh elimi- 65 natlng cylinders andtherefore apply the proper directional pressure on thebacklasheliminator in accordance with the direction of movement of thetable. When the plunger I11 is moved upward to a stop positioncorresponding todown- 60 ward movement of the lever I19 the plunger I94is not moved from the position shown in Figure 18 so that the sameconnections app y to the backlash eliminator in the stop position of theplunger as in the feed position thereof. How- 65 ever, when the plungerI11 is moved downward to a rapid traverse position corresponding toupward movement of the lever I18 the plunger I94 is then shifted to theright. In this position the canneiure' 243 will interconnect ports 244and 7 246 with port 249 which means that if the port 249 happens to beunder pressure as determined by the position of plunger I93 then equalsure will be applied to opposite ends of the shifter rod 12 of thebacklash eliminator and 75 it will assume a more or less centralposition in which the backlash eliminator is rendered noneflective. Ifthe port 240 happens to be connected to exhaust, due to the position ofplunger I93, the result is the same in the sense that the same pressureexists in cylinders 11 and 18 so that the shifter member 12 will againassume a central position and the backlash eliminator will benon-effective. It will thus be seen that the eiTect of the backlasheliminator is automatically taken care of in accordance with theposition of plunger I11.

' The plunger I11 may also be moved to its several positionsautomatically by suitable trip dogs carried by the table acting on aplunger 249 which is operatively connected by a ball ended stud 258 tothe oscillatable and axially movable member I83, the member 250interfitting in a hole 25l formed in the member I83. Referring to Figure16 it will be seen that the plunger 249 is on the side of pin I86opposite to plunger I11 so that the plunger 249 will move up when theplunger I11 moves down and vice versa, but that plunger 249 will havethe same directions of movement for the same results as the handle I18so far as vertical movements are concerned, but when the lever I18 ismoved counterclockwise the plunger 249 will be rotated clockwise andvice versa. This results in the hand lever I18 havingdirectionalgcontrol in that when it is moved clockwise or to the left tothe position shown in Figure 16 the table will move to the left and whenmoved counterclockwise or to the right from the position shown the tablewill move toward the right.

An auxiliary plunger 252 is supported adjacent the plunger 2.49 which isutilized solely for automatically stopping the table regardless of thecycle in which it is moving or the rate at which it is moving and thisplunger has a shoulder 253 formed thereon for engaging the end of afixed bushing 254 and a spring 255 interposed between the lower end ofthe plunger and the housing for holding the plunger up as limited by theshoulder 253. The plunger has an intermediate enlarged portion 256 inthe side of which is formed a slot 251 in which rides a lever 258pivoted on a fixed pin 259. This lever has a bifurcated end in which ismounted a pawl 260 oscil- "latable on a pin 26I. "The pawl.260 has anend 252. The pin 264 acts to hold the lever 258 at a sufficient angle topermit upward movement of the plunger 249 to a rapid traverse positionwithout interference from the pawl 268. The plunger 265 serves totransmit motion from the plunger 252 to the .lever 258 upon downwardmovement of the plunger and the lbst motion resulting from, compressionof spring 266 permits the pin- 264 to move relative to the groovewithout too much friction.

The pawl 268 has a shoulder 265 which will engage the top of afixed pin266 as it approaches the limit of its downward movement and in suchtimed relation that the end 262 of the pawl will be moved oil of theshoulder 263 after it has moved the plunger 249 downward a suificientmovement to a stop position. This will rotate on the top of the lever.The idea of this mech: anism is to permit the plunger I11 to be returnedto its same position before it was depressed by the stop plunger or evento a difierent position, while the stop dog is still holding the stopplunger in a depressed position. In other words, the mechanism acts todepress the plunger 249 and then automatically disengage itselftherefrom whereby it may be immediately moved manually without thenecessity of manually moving the table to get the stop dog ofi of thestop plunger. For instance, on a continuous reciprocating cycle withwork fixtures mounted on opposite ends of the table whereby one may beloaded while the cutter is acting upon the other, a stop dog may bepositioned to stop the table with the cutter intermediate the twofixtures so as to insure that lever I18 to the proper position wherebythe.

cycle will continue.

Energization of the various solenoids is controlled by four doublepoled, double throw switches indicated generally by the referencenumerals 268, 269, 210 and 21I in Figures 11 and 21. These switchesareconventional commercial type limit switches having a central pivotedarm 212 and rollers 213 in the extremities of the arm for engagement bysuitable cam surfaces for throwing the switch.

These switches are mounted in a separate compartment 214 located in thecontrol bracket underneath the compartment 215 which houses thehydraulic detent mechanism. Since the hydraulic detents exhaust directlyin the compartment 215 and the return oilcollected by a sump pipe 216communicating with the fioor of the compartment it is necessary tOprevent oil from flowing into the lower compartment. To prevent this andstill make it possible to pass the control plunger into the lowercompartment a bushing 211 is fixed in the floor of compartment 215 andextends upward to a height sufficient to maintain the top thereof abovethe normal level of oil that might accumulate in the upper compartment.The plunger I11 has an axially drilled hole in which is inserted andfastened a control rod 218. This control rod extends through the lowercompartment and is journaled at the lower end in a bearing 219.

The control rod 218 has a first cam member mediate or feed position/tothe rapid traverse position it has no eflect on the switch. This memberalso has a second cam portion 282 for operating switch 218 upon eachrotary movement of the plunger.

The member 218 has a. collar 283 secured thereto for operatingswitclr269 upon movement from its extreme lower position to its intermediate position, or vice versa, but upon movement from its intermediateposition to it's extreme upper or stop position it has no efl'ect on theswitch.

asgshown in Figure 31,.the member 218 has a engages with a mutilatedgear 285 secured to shaft ,geaii'se ent 284' inned the hi the pawl 268in a counterclockwise direction gm p reto w ch inter against the urge ofa spring plate 281 288 upon whiehis pin d swwch the member 281 relativeto the movement of member 218 the second lobe 289 will have suflicientmovement to reset the switch whereby the switch is thrown twice for eachrotary movement of member 218 regardless of the direction of thismovement. 1

The manner of electrically connecting these switches to the solenoids ismore particularly shown in Figure 21 and the operation of the circuitwill be explained from this figure. It will be noted that throughout thedescription of the trip plunger reference has been made to the fact thatthe trip plunger is shown in a position to yield a. feeding movement ofthe table to the left. The various control switches shown in Figure 21.are also positioned so as to yield this movement. The main switch 290serves to connect power to the entire trip control circuit. Startingwith pole 29I of switch 290 the current flows to the inner connection292.where it divides into branches 293 and 294. Branch 293 is connectedto pole 294 of switch 210 and since the switch member 295 thereof isclosed the current continues through line 296 and solenoid I15 back tothe other main switch terminal 291. viously stated, energization ofsolenoid I15 will shift the direction determining clutch to yieldmovement of'the table to the left. It will be noted that the otherbranches connected to line 293 are open at this time.

Current flowing through line 2931s connected by an interlock switch 298associated with the starting lever 299 which is connected to poles,

300 and 30I of the switch levers 302 and 303 respectively of switch 263.The switch lever 302; being closed, causes the current to pass throughsolenoid I13 and back to pole 291. The solenoid I13 is the stop solenoidand is controlled oppositely tothe manner of controlling the feed andrapid traverse solenoids in that the. stop solenoid is always energizedexcept when the machine is to be stopped when it is de-energized,whereas the feed and rapid traverse solenoids are normally de-energizedand are only energized when their particular functions are to beperformed.

The idea of. this arrangement is that should any I break or failureoccur in the electrical circuit the stop solenoid will be tie-energized,whereby a spring will come into action to immediately stop the machine.

Since the switch member 303 is also closed the current flows throughline 304- to pole 305 of switch 269, and since the switch member 306thereof is closed, the current continues and energizes the feed solenoidwhereby the feed-rapid.

traverse-clutch is shifted to cause movement of the table at a feedrate. I

It will thus be seen that in the feed left position of the trip plungerthat the stop solenoid, the feed solenoid and solenoid I15 are allenergized.

In a reciprocating cycle it is usually desirable after completing a feedmovement to reverse the table and to return it at a rapid traverse rate,or in other words, to simultaneously effect a change in directionand-rate.. Thisis automatically effected in the following manner. The

trip plunger 249, as shown in Figure 35, has a mg 301 which projectstoward 'the table when the plunger isfi n the rotary position shown, andthis As prelug is adapted to be engaged by a dog 308 which has a bevelface 309 for contacting the underside of the lug 301 for lifting thesame. This lifting movement of plunger 209 will, however, be a-.downward movement of plunger I11 due to the 5 manner ofinterconnecting these members as previously explained. Downward movementof member I11 will yield, of course, a rapid traverse movement.

It is desirable, however, that the direction be changed also and asecond dog 3I0 is positioned on the table adjacent dog 308 and this doghas an encircling arm for engaging a wing 3I2 which projects from theside of plunger 249, as more particularly shown in Figure 35. These two15 dogs are positioned to contact the plunger almost simultaneously sothat both movements will be carried out-substantially together but inthe following speciflc manner. The plunger is moved downward a sumcientamount to move the hydraulic detent mechanism to a central positionwhich would correspond to the loading operation ofa load and firemechanism. lguring this movement the plunger is rotated, and as soon asthe rotation starts the M3188, shown in Figure 31, throws switch 2".This producesthe first effect on the electrical circuit which is toclose the switch-member an of switch 2'.

switch may be termed a by-pass switch in that it closes a parallelcircuit around the switch member 306 of switch 269.

The other switch member 3 of switch 2 is simultaneously opened with theclosing of switch 3 I 3 which thereby breaks the circuit from line 293.to the rapid traverse solenoid I14 at two points because the switchmember 3I5 of switch 269 is open at this time. This effect conditionsthe circuit'for operating switch 269 without breaking the feedconnection.

Since the plunger is being rotated by dogl3ll 40 Y the lug 301 on theplunger is gradually being ro-' tated out of the path of dog 308, andwhen the plunger has completed its rotary movement the lug 301 will becompletely out of the path of dog 308. It is, therefore, not onlynecessary to complete the axial movement. of the plunger before therotary movement is completed, but also to complete both movements asclose together as is possible. Asa matter of fact the vertical move-.

ment is completed first which operates through.

the detent mechanism to throw switch 269. It will be noted that in the.half-way position of the switch members 306 and 3 I 5 that both circuitsare momentarily broken whereby the switch member 3I3 of switch 211electrically maintains the feed 5 circuit and insures that nothinghappens until the switch member 3I6 has been closed. It will be noted;however, that even after the switch member 3 I 5 has been closed thatthe switch member 3 is still open. From this it will be seen that theswitch 269 has in effect been prepositioned without in any waydisturbing the continuation of the present cycle of the machine.

The last thing that happens is that the plunger completes its rotary.movement which throws switch 210 to change the direction andsimultaneously resets switch 2" in the position shown in Figure 21whichthereby completes the circuit through the switch member 3I5 ofswitch 269 and thus operation of the rapid traverse solenoid H14. Itwill be noted that throughout these changes that no eff-"ct was producedon switch 268. the control. cam portion 23I therefore merely movingdownward-away from the switch and leavingfitset in its previousposition. will result in movement of the table toward the right at arapid traverse rate and will shift the manual control lever I9I to thedotted line position I90 in Figure 11.

Before the next feeding operation takes place it may be desirable toplace a stop dog, such as 3 l 6, on the table, as shown in Figure 1,which will depress the stop plunger 252 to insure that the work has beenproperly loaded before the next feeding operation starts. Depression ofthis stop plunger will, through the interconnecting mechanism previouslydescribed, cause upward movement of control rod 218 which willsimultaneously operate switches 268 and 269, the switch parts in 269assuming the position in which they are shown in Figure 21 and theswitch members 302 a and 303 of switch 268 being opened. In spite of thefact that the switch member 306 is closed, still the switch member 303is opened and since in serial relationship therewith the feed solenoidwill be de-energized. Also, solenoid I13 will be (ls-energized due toopening of switch member 302, but de-energization of this solenoid willcause operation of the control cams in a manner to stop the machine.From this description of the control circuit it is believed that itsmanner of operation will be clearly understood and that it is merely amatter of selecting the proper control dogs and suitably positioningthem on the table to produce any conventional cycle ofoperation desired.I

The switch member 298, previously referred to, is under control of thespindle starting control lever 46 and is only closed when this lever isin a position to cause rotation of the tool spindle.

Attention is also invited to the fact that the plunger 249 has anadditional lug 3I1 by which the same is axially moved by dogs duringmovement of the table toward the right. It is also provided with anotherwing 3I8 on the opposite sidefor engagement by a reversing dog when thetable is moving toward the right.

A constantly rotating means has been provided to which the control camsmay be selectively coupled for positioning the several clutchescontrolled thereby. This means may be considered as a. constantlyrotating branch transmission driven by the prime mover and inde: pendentof the rate and direction clutches. The bevel gear I00, Figure 2, iscontinuously driven by the prime mover, aspreviously described, and hasintegrally formed therewith a spur gear 3I9 which meshes with a largegear 320 of a couplet 32! supported for free rotation on the elongatedhub of gear IIZ, the smaller gear 322 of this couplet driving the spurgear 323.

This gear, as shown in Figures 10 and 30, is supported for free rotationco-axially of the shaft 324 and is connected to it by an overloadrelease clutch comprising V-shaped clutch teeth 325 formed integral withthe spur'gear 323 and similarly formed teeth 326 formed on the end of asliding clutch member 321 which is splined on the end of a hollow sleeve328, the sleeve being connected as by a set screw 329 to the shaft 324.

A stud 330 is threaded in the sleeve 328 and projects through one endthereof for supporting a spring 33I, one end of which engages a washer332 which is interposed to transmit movement to the end of an overloadswitch lever 333. The other end of the spring abuts a shoulder 334 invtegral with the sliding clutch member 321. Under normal conditions, thespring will hold the clutch 321 into engagement with the clutch teeth ofgear 323 but should the-load on the cams, which are rotated by shaft324, become excessive the member 321 will be retracted and through thespring actuate the lever 323 to throw a switch that will start themachine.

The shaft 324, as shown in Figure 10, is journaled at one end in asleeve 335 carried by a fixed part of the housing and at the other endin a sleeve 336. The intermediate portion of the shaft extends throughthe direction determining cam I11 which is journaled at 331 and 338 forfree rotation relative to shaft I24.

A spur gear 339 is keyed to shaft 324 for continuous rotation therewithand intermeshes with a second spur gear 340 mounted for free rotationrelative to a shaft 34! upon which is keyed the rate determining cam I10which is rotatable with the shaft and is also axially movable relativeto the shaft.

The gears 339 and 340 constitute continuous rotating termini of theconstantly driven branch transmission to which the direction and ratedetermining cams may be selectively interconnected for intermittentrotation thereby. The type of connecting means utilized in each case isthe same and comprises a roller cam clutch, the details of which aremore particularly shown in Figure 8.

Each of the gears 339 and 340 has an annular flange 342 projecting fromthe side thereof for encircling three rollers equally spaced about theperiphery of an equilateral triangular shaped cam portion 344 which, asshown in Figure 10, is an integral part of shaft 34L The sleeve 345 hasa slightly reduced portion 346 which interiorly telescopes the flange342 of gear 340 and has three equally spaced slots 341 out therein, asmore particularly shown in Figure 4, in which are inserted the rollers343. The portion 346 also has three additional equally spacedrectangular shaped openings 348, and intermediate of the slots, and ineach opening there is pivoted a friction shoe 349 which is urgedradially outward by springs 350 carried by the portion 346.

The shaft 34I also carries a fixed pin 35I, Figure 7, which extends intoan opening 352 formed in the sleeve 345 and a spring 353 is interposedbetween one side of the pin and the sleeve 345 which acts when the partsare free to cause rotation of the sleeve 345 in a counter clockwisedirection, as viewed in Figure '7, relative to the shaft 34I. The sleeve345 also has three radially extending lugs 354, 355 and 356 which lie indifferent planes perpendicular to the axes of the shaft as moreparticularly shown in Figure 10.

Three pawls, 351, 358 and 359, lie in the respective planes of theselugs for engaging the same and stopping rotation of the cam at desirablepoints in its movement. The method of operation is as follows.

In Figure 7 the sleeve 345 is held against rotathe cam 344. Thismovement will be assisted by the frictional engagement of the shoes 349with the inside of the flange 342 because the flange and gear 340 arecontinuously rotating, as viewed in this figure, in a counterclockwisedirection. This wedging action will cause the cam 344, shaft 3 andshifter cam I10 to rotate therewith. This rotation will continue untilone of the pawls 351, 358 or 359 is moved into the path of itsrespective co-acting lug carried by the sleeve 345 whereby the sleevewill immediately stop rotating. Stoppage of the sleeve means that therollers 343 will immediately be held stationary while the outside sleeve342 will continue in a counterclockwise direction and the cam portion344 will continue in a counterclockwise direction momentarily due to itsown inertia and the inertia of the parts connected therewith, wherebythe roller will no longer be in a wedging position and rota tion of thecam I10 will immediately stop. Since the pin 35I shown in Figure '1 hasonly a small amount of clearance between itself and the opening insleeve 345, any overrun of shaft 34I beyond the predetermined amountnecessary to loosen the rollers 343 will be immediately checked.

In order to additionally insure that the cam member I10 is stoppedrotatively in the upper position and held in such position againstintermittent movement a detent mechanism has been provided comprising adisc 360 keyed or otherwise secured to the end of shaft 34I and apivoted detent member 36I shown more particularly in Figure 29. The disc360 has a pair of L-shaped notches 36I cut in the periphery thereof forsucreason that the cam I10 has only two rotative positions which areapart, one of which yields rapid traverse and stop and the other ofwhich yields feed. The rapid traverse-stop position of the cam isdistinguished, however, by providing for axial movement of the camwhereby the cam has one axial position for rapid traverse and a secondaxial position for stop.

The detent 362 is continuously urged into engagement with the peripheryof the member 360 by spring 363 and as the shaft'34I approaches a givenposition and the detent snaps home the bevel face 364 on the detent willinsure completion of the movement since the shaft 34I rotates in acounterclockwise direction in this view and the friction between thepoint 365 of the end of the lever and the, bottom of the notch issufiicient'when the power means has been disconnected to prevent anyinadvertent movement.

The same form of roller cam clutch means is utilized for connectingdrive gear 339 with the direction determining cam I1I but in this casethe sleeve 345' is provided with only two lugs 366 and 361 since it isonly necessaryto rotatively position the cam I1I in two positions.

Similar means have also been provided for the cam I1I which are shownmore particularly in Figure 28 and consist of parts similar to theprevious detent mechanism including a wheel 368 having L-shapednotches369 and a spring pressed detent lever 310. The action is the same asthat previously described.

The cam I1I has a groove 3" which is shown in expanded view in Figure34. A follower 312 attached to the end of lever 313 rides in this grooveand when it occupies a position corre sponding to the dash and dot line314 the direction determining clutch is shifted to yield a leftwardmovement of the table. The cam is stopped in this position by thefollowing mechanism. The solenoids I15 and I16 have plungers 315 and 316respectively which are connected as by a ball and slot connection 311 tolevers 318 and 319 respectively. These levers are both secured to ashaft 380 and the lever 318 has an arm 38I which operates through a balland slot connection 382,

a lever 383 secured for rotation of shaft 384.

The solenoids I15 and I16 are respectively push and pull solenoids inthe sense that when the solenoid I15 is energized the plunger 315 movesupward, which simultaneously rotates the shaft 380, as viewed in Figure25, in a clockwise direction, and since the lever 319 is also secured toshaft 380 it will be moved upward also. Upon energization of solenoidI16 the plunger 316, and thereby the lever 319, will be'pulled downwardand the shaft 380 will be rotated in a counterclockwise direction. Thiswill also cause downward movement of lever 318 and plunger 315. It willthus be seen that alternate energization of these solenoids will causealternate clockwise and counterclockwise movements of shaft 384.

This shaft has a pair of pawls 385 and 386 integrally connectedtherewith, as shown in Figure 26, and the position of the parts is suchthat when the solenoid plungers are up the pawl 385- is moved .inwardinto the path of lug 361 which will stop the cam I1I in the positionshown in Figure 2, causing the clutch I03 to interconnect shaft 91 withbevel gear 98 and thereby movement of the table to the left.

Downward movement of the solenoid plungers will withdraw pawl 385 fromthe path of lug 361 and move the pawl 386 inward into the path of lug366 whereby the cam will rotate through an angle of 180 to shift theclutch I03 to its other extreme position and thereby change thedirection of movement of the table.

The pawls 351, 358 and 359,shown in Figures 5, 6 and 7 are connected tothe various solenoids in the following manner. The pawl 358 is securedas by a pin connection to shaft 381 which extends parallel to the camI10 as shown in Figure 4 and has secured, as by a pin connection, alever 388 which has a ball and slot connection 389 to plunger 390reciprocably mounted in the feed solenoid I12. A spring 39I is mountedto act in a direction to produce a constant urge that will tend towithdraw the pawl 358 from the path of lug 355 so that this pawl is onlyaffected when the solenoid is energized. v

The pawl 359 is integral with its operating lever 39I and these partsare mounted for free rotation relative to shaft 381. The end of lever 39I' has into an effective position, which as previously explained,insures-stoppage of the machine upon any failure of the electricalcircuit.

The lever 393 has a pin 395 projecting from the side thereof intoengagement with the bifurcated. end 396 of a bell crank 391, rotatableon a fixed pin 398. This bell crank has a ball and slot connection 399with a reciprocable plunger 400,

which, as shown in Figure 9, has a cam follower.

40I journaled on the. end thereof and engaging cam groove 402 and cam110.

The plunger 400 also has a ball and socket connection 403 with a lever404 which is pivoted intermediate of its length on a fixed pin 405. Theother end of this lever has a ball and socket connection 406 with asecond plunger 401 having a rotatable cam follower 408 in the endthereof adapted to interengage the cam groove 409 formed in cam I10.

The parallel plungers 400 and 401 constitute the means, in conjunctionwith the cam grooves 402 and 409 for shifting the cam I10 axially. Inother words, when the stop solenoid became deenergized and the spring39I moved the pawl 351 into the path of lug 354 it simultaneouslythrough the pin 395, bell crank 391, moved plunger 400 forward intoengagement with cam groove 402 and approximately at the point in the camgroove intersected by the dash and dot line 4I0, Figure 33. The cam, asviewed in this figure, is moving in the direction of arrow 4| I, whichmeans that as the roller 402 came into engagement with the curved wall4I2 of the cam path the cam was bodily shifted in the direction of arrow3.

If, now, the stop solenoid is assumed to be energized and the pawl 351withdrawn from the path of lug 354 the plunger 400 would immediatelybewithdrawn from cam groove '402 and plunger 401 simultaneously movedforward to move the roller 408 into the cam groove 409 approximately atthe point intersected by the line 4I4. At the same time that the pawl351 is withdrawn the cam I10 will continue to rotate in the direction ofthe arrow 4 and the roller 408 will engage the curved wall 4I5 of camgroove 409, and since the roller 408 is bodily fixed the cam I 10 willbe shifted in a direction opposite to arrow 4| 3. It will thus be seenthat each time the-stop solenoid is energized, the cam I10 is shiftedaxially and the relative position of the pawls 351, 358 and 359 withrespect to their co-acting lugs is such that upon withdrawal of eitherpawl 358 or 359 the cam will make 180 of revolution before lug 354.willengage pawl 351.

A third'cam groove M6 is formed in the cam I10 intermediate the othercam grooves for receiving the roller 4 I1, Figure 27, fixed to the endof lever 4I8 pivotally mounted on a fixed pin MB. This lever has a crank420 in which is formed a bore 42I for receiving a spring 422 whichsurrounds a rod 423 attached at oneend as by a bifurcated connection 424to the shifter 425 for the feed rapid traverse clutch I I0. The shifteris also mounted for free rotation relative to the pin 9. The rod 423extends through the closed end 426 of the bore 42I and has a couple oflock nuts 421 threaded on the projecting end thereof. This mechanismconstitutes a yieldable joint in the feed rapid traverse shifter and itwill be noted it is due to such construction that upon movement of theroller 4" about the fixed end 9 in a counterclockwise direction that theshifter 425 will be moved positively to engage the rapid traversefriction clutch but upon movement of the roller M1 in a clockwisedirection the shifter 425 will be impositively moved due to compressionof spring 422 in case the teeth I52 of member I I0 have not properlyaligned themselves for interengagement with teeth I53 carried by thefeed drive gear I4I. In other words, should there be a momentary delayin interengagement with these teeth the clutch shifting means shown inFigure 27 will yield sufliciently so that the roller 1 can still followthe cam groove without damage to the parts.

It will be noted from Figure 3 that the roller 4" is out of phase withthe roller 40I, which means that when the cam stops with the roller 402on the line 4I4, Figure 33, that the roller H1 will be at a position inits cam groove represented by the line 428 which will correspond to therapid traverse position. If the cam should stop with the roller 402 onthe line '4I0 the roller 4I1 will be in a position in its cam grooveintersected by line 429 which will correspond to the feed position. Itwill be noted, however, that when the cam I10 is bodily shifted axiallyin the direction of arrow 4 I3 that the roller 4 which is then in aposition corresponding to line 426, will be shifted toward the left inthis figure and just a sumcient amount to move the clutch'member IIO toan intermediate position whereby both the rapid traverse and the feedclutches are disengaged and no power is being transmitted to the table.

The cam I10 has an additional function and that is to apply a brakingmeans whenever. the cam is moved to -a. stop position. As previouslyexplained, the clutch I56 in Figure 3 serves to interconnect the driveshaft, I01 with the gear I54 and this gear is normally held againstrotation whereby, "upon engagement of the clutch I56, the gear I54serves as a braking means for the shaft I01. The engagement anddisengagement of this clutch is controlled automatically by the cam I10through the following means. A shifter lever 429 is pivoted at 430 andhas one end connected to the clutch I56 and the other end connectedto alink 43I which serves as a connecting means between the lever 429 and acam operated lever 432. The lever 432 is pivoted on a fixed pin 433 andhas a cam roller 434 journaled at its opposite end for engagement withthe cam groove 409.

The lever 432 is so positioned that the roller 434 is 90 out of phasewith the plunger ,401, which, as shown in Figure 9, has aroller 408selectively movable into the groove. Upon comparison with Figure 33 it.will be seen that the roller 434 will be positioned on the line 428when the roller 402 has axially shifted the cam I10 to the dash and dotposition shown in Figure 33, whereby the lever 432 will be shifted insuch a direction as to effect an engagement of the clutch I 56, which,in turn, will act as a braking means to immediately stop the movement ofthe table. In other words, any time that the cam I10'is axially shiftedto stop the table it will simultaneously apply the braking means. Thisconditions the mechanism for manual rotation of the table when 3' thepower is disconnected therefrom and at the.

same time operates to disengage the gear I54 from the drive shaft I01during power operation of the table so that inadvertent engagement ofthe manual control lever I6I with the shaft I53 will be ineffective andprevent damage to the mechanism or injury to the operator.

The entire electrical equipment of the machine is connected ordisconnected relative to an out side source of power by a pair of pushbuttons 435 supported on the front of the machine in a suitable housing431 and an electrical conduit 438 extends therefrom .to the end of themachine for carrying the wires by which the push buttons are connectedto the main switching mechanism. This cable also carries the wires fromthe control bracket on the front of the machine to the feed solenoidsand constitutes means exterior of the bed of the machine forinterconnecting the control switches in the control bracket to thecontrol mechanism mounted in the transmission box on the end of themachine. 3

These push buttons are more particularly shown in the electricaldiagram, Figure 21. A depression of the starting button 436 closes'thecir-- with contact 443 due to the push button 431- .being in a normallyclosed position. Contact 443 is connected through conduit 444, interlockswitch 445, and conduit 446 to the main line 441. Energization of theunit 439 will close the switch of the three-phase system comprising thestationary contacts 448, 449 and 458, which are simultaneously connectedwith the movable contacts 45I, 452 and 453 respectively. This willcomplete the circuit to the table operating member 454, the spindleoperating motor 455 and the coolant pump operating motor 456.Simultaneously operable with the closing of these contacts is a secondswitch member 451 which interconnects contacts 458 and 459 so that thecircuit through the switch operating device 439 is now completed throughthe line 468 which terminates in the contact 452 of push button 431 sothat the push button 436 may now be released without stopping themotors. The device 439 will thus be energized to hold the switch closedduring the operation of the machine, and when it is desired to stop themachine the operator merely depresses the push button 431 whichwill openthe circuit. through the device 439, which will automatically cause theswitch contacts to separate.

Attention is invited to the fact that the switch 298 is so connected tothe supply lines as to be controlled by the switch contacts 452 and 453so that whenever the operator stops the machine he will automaticallydisconnect the current from the solenoids and thus prevent a waste ofcurrent. The switch 445 is mounted in the switch box 46I shown moreparticularly in Figure 12 and supported on the side of the transmissionbox, as more particularly shown in Figure 1. This switch is normallyclosed but is adapted to be opened by a lever 462 which isinterconnected for automatic operation by the lever 333, previouslydescribed in connection with Figure 30. In other words, when the movableclutch member 321 in that figure is shifted axially it causes rotationof lever 333 and thereby of arm 463, which, as shown in- Figure 12,carries an adjustable block 464 on the end thereof for interengagementwith a roller 465 carried in the end of a pivoted arm 466. The block464, as shown in Figure 32, has a wide upper face 461 upon which theroller 465 rides so that upon upward movement of the block 464, due toupward movement of the lever 463,

it will cause upward movement of the arm 466, and by means of a pin 468acting on the face 469 of lever 462, move thesame outward against thetension of spring 418 to disconnect the switch and, upon completion ofthis movement, the pin 468 will.drop into a notch 4 formed in the lever462 to hold the lever andthereby the switch in a disconnected position.This will break the circuit through the line 444 and causedeenergization of the switch operating device 439. Re-engagement can bemanually effected by the operator rotating the lever 462 suflicient todisengage the pin 468 from the-notch and permit the clutch 321 tore-engage itself if the condition which caused disengagement has beenremoved.

Means have also been provided for preventing operation of the table at afeed rate when the spindle is stopped and the switch 298 shown in Figure21 is mounted in theswitch bracket 412, Figure 14, and has a secondswitch member 413 associated therewith and so positioned that the switch413 is open when the switch 298 is closed, or vice versa. These twoswitches are operable by an arm 414 carrying a pair of rollers 415 inopposite ends thereof for engagement with. a

. switch operating arm 416 connected with the spindle clutch controllever 46. In other words, when the lever 46 is thrown to engage thespindle clutch shown in Figure 22, the switch 298 will be closed topermit operation of the feed solenoid so that the table may be moved ata feed rate, but should the switch lever be in a stop position theswitch 298 will be open and the switch 413 will be closed. Should thespindle control lever be thrown to a stop position during .the feeding'movement the'opening of switch 298 will break the circuit 299 wherebythe stop solenoid will be de-energized, causing engagement of the pawl,and the feed solenoid I12 will be simultaneously deenergized, permittingdisengagement of its pawl so that the control cam I18 will rotate to astop position. The spindle interlock switch thus acts to automaticallystop the feeding movement when the spindle control lever is thrown to astop position.

If the spindle control lever is in a stop position and the solenoidsI12, I13 and I14 are deenergized, which means that the switches 382 and383 are open, and attempt is made to move the table at a feeding rate byclosing these switches, the fact that the switch 298 is open wouldprevent the attainment of this result. The table may, however, be movedat a rapid traverse rate due to the fact that the switch 413 is closed,because it is possible to energize the rapid traverseand stop solenoidsbut impossible to energize the feed solenoid. This would be accomplishedby throwing the switches 386 and 3I5 to the opposite position shown inFigure 21 whereby the current from switch 298 would flow through line293, switches 3l4 and M5 and then in parallel, first throughthe rapidtraverse solenoid I14 to switch 298 and secondly. through switch 413,line 299, switch 382, stop solenoid I13. and then to switch 298 wherebythe stop pawl will be withdrawn and the rapid traverse pawl moved to anoperating position. The current flowing in'line 299 will, however, bestopped from flowing to the feed solenoid due to the opening of switch386.

The spindle stop interlock switch thus acts to stop the feeding movementat any time that the spindle clutch is dis-engaged and also acts whenthe spindle clutch is standing in a dis-engaged position to preventmovement of the table at a feed rate, but will permit movement of thetable at a rapid traverse rate.

There has thus been provided an improved milling machine structure inwhich the transmission and control mechanism are on the exterior of thebed of the machine so that the interior of the bed may be utilized forthe reception of chips and coolant without interference fromtransmission or control mechanism parts,'and in which the transmissionis built and assembled as a unit

